Origin of thirst

before 900;Middle Englishthirsten (v.), Old Englishthyrstan, derivative of thurst (noun); cognate with Dutchdorst,GermanDurst,Old Norsethorsti,Gothicthaurstei; noun has -i- from the v. or from thirsty; see toast1

Old English þurst, from West Germanic *thurstus (cf. Old Saxon thurst, Frisian torst, Dutch dorst, Old High German and German durst), from Proto-Germanic *thurs-, from PIE root *ters- "dry" (see terrain). Figurative sense of "vehement desire" is attested from c.1200.

v.

Old English þyrstan (see thirst (n.)); the figurative sense of the verb was present in Old English. Related: Thirsted; thirsting.